Embodiments of the present application generally relate to real time, bi-directional communication access control systems. More particularly, but not exclusively, embodiments of the present application relate to bi-directional communication access control systems having intelligent access control devices or points that are capable of making local access control decisions.
Often, real time access control devices, such as, for example, electronic locks, that utilize wireless communication are battery powered. However, at least in an attempt to extend battery life and/or otherwise conserve electrical energy of the electrical power sources of the access control devices, real time communications involving such access control devices are often generally limited to a single direction using a master-slave topology. In such situations, in at least an attempt to accommodate power consumption characteristics of the employed wireless protocol, a master device, such as an access control panel, may initiate wireless contact with a slave device, such as an access control device, when the master device has a message to deliver to the slave device. However, if the slave device has a message to deliver to the master device, the slave device typically has to wait until the master device initiates contact with the slave device before the message can be delivered from the slave device to the master device.
Compared to at least certain access control devices that are generally powered via a hard wired connection, such as, for example, a hard-wired connection to a utility power source, wireless, battery powered access control devices that utilize master-slave topology can have relatively limited and/or impaired end-user applications. For example, certain end-users may generally have a preference for low-latency of communication up to the access control device to the host system, which can, in at least certain situations, be associated with experiencing relatively dramatically slower timing when the host system wants to push a message down to the access control device. Efforts to address such issues have included the use of access control devices having real time, bi-directional capabilities. Yet, as previously mentioned, power consumption constraints and/or associated energy conservation typically mandates that such access control devices be hard wired to a power source. Further, hard wired access control devices, and the associated constraints, such as, for example, the need for hard wiring to a utility power source, has certain drawbacks and limitations that are not associated with the use of battery powered access control devices, including, for example, the costs of installing and maintaining the wire used to deliver electrical power to the access control devices.
Additionally, wireless and wired access control devices often utilize a central point, such as, for example, an access control panel (ACP), to make an access control decision in real time. However, in at least an attempt to ensure all access control requests are processed in a timely fashion, use of an ACP for making decisions for access control devices can result in the communication channels linking the ACP to the access control device being dedicated for the purpose of access control and/or having to satisfy relatively stringent or enhanced capacities for reliability. Further, attaining such extra capabilities of the networking medium can increase the cost for access control. For example, if wireless communication methods are used, channels or frequencies used to provide communication channels linking the access control devices to the ACP may be selected based on the ability to attain a particular level of performance that can reliably support such the associated demands. Often, reliably attaining such performance entails the selection and use of certain custom or regulated wireless technologies. Further, at least in the case of use of certain regulated wireless technologies, sales of the access control devices and/or of at least certain components of the system are generally limited to the certain geographic jurisdictions that certify that particular regulated wireless technology. Conversely, rather than utilizing custom or regulated wireless technologies, if a global wireless standard is used, such as, for example, Wi-Fi, often dedicated networks or channels may be incorporated into the system to attain the access control reliability and/or performance criteria, which can place a relatively large burden of ownership on the end-users.
Additionally, power outages can be a relatively prevalent issue for centralized access control decision making. For example, for access control devices that rely on an ACP to make decisions in real time, the loss of communication with the ACP can result in a degraded mode of operation. Thus, in at least an attempt to deal with such issues, some systems may install back-up batteries and/or generators that can provide power during utility power outages so as to allow access control to continue through the ACP. Yet, besides adding to the costs associated with the system, for at least certain battery powered access devices, even after resuming communication with the ACP, the history of events that occurred during the loss of communication are typically lost and non-retrievable.
Additionally, wireless access control devices that are capable of making access control decisions at the door typically require touring with an update tool to update the local access control database. Alternatively, such wireless access control devices can rely upon periodic or pre-negotiated times in which the access control device is to communicate with the ACP. Yet, such procedures can be both timely and costly, and result in delays in updates for the system and/or devices of the system.